1. Field of the Invention
The present invention relates to a method for identifying natural and synthetic diamonds, and particularly to a method of rapid identification of natural and synthetic diamonds using a third-order Raman spectra.
2. Related Art
Raman spectroscopy is used as a diagnostic tool for diamonds because each carbon allotrope displays a clearly identifiable Raman signature, it is non-destructive, requires little or no specimen preparation. Raman scattering from diamond has been disclosed by prior literatures, which describe the fundamental properties of the Raman spectra of natural and synthetic diamonds. Most natural untreated diamonds exhibit nitrogen-vacancy crystallographic defects and exhibit a series of typical second and third order Raman peaks as shown in FIG. 1. Crystallographic defects causing the Raman peaks for natural untreated diamonds are not fully understood. Therefore, it is a pressing issue to find out a method for rapidly identifying natural and synthetic diamonds through the existing Raman technique.